Sailboats of conventional design either mono-hull or multi-hull depend on the flotation or displacement of the hulls to counteract the wind force (torque) which makes them tip or heel. This heeling condition loads the water with added force which causes more displacement and therefore more friction. Even the use of hydrofoils to counteract heeling forces load the water. Without exception (all sailing systems except the ones later noted) the wind force must be balanced or the boat will roll over.
Sailboats of conventional design when heeling or tipping from the wind pressure spill out from their sails wind which is wasted and its energy lost. This lost energy is only saved by balancing the boat with displaced weight. Therefore, a conventional boat can only use as much energy as can be balanced with the weight of the system which limits the wind power a conventional sailboat can handle.
One exception to this rule is a sailing surf board. This system requires the payload or passenger to hang from the sail by means of a boom or bar. This prevents the wind from blowing the sail over and into the water. It is therefore a requirement that the passenger exactly balance the wind forces with his own body weight. This system does not load the water with any excess pressure, but it is limited by the force the passenger can balance with his body weight.
Another exception to this rule is employing a kite of sufficient size to propel craft by the pull of its tether string. This system works well downwind and even to some degree across the wind, but would not work making to windward.
Another example of sailing craft approaching the non-heeling system was invented by Frank Delano and Bernard Smith of Acorn, Virginia, which employs a single payload supporting hull with rods and contrivances to attach a sail some distance downwind from the payload hull. The sail is supported by devices called hydrofoils or hydrofoil shaped floats. These hydrofoil floats also provide steering by means of a lever. This boat is described as speedy. In light to average wind velocities this system hasn't any particular disadvantages. In higher wind velocities the windforce must be accounted for by added loading on the hydrofoils which has to produce added friction with the water. In severe wind velocities this craft probably would bury the sail and hydrofoils in the water and severely strain the system which would prevent further increase in forward velocity. This craft is dubbed by the inventor as a monomaran. A patent for this invention was not indicated in an article in the section "What's New" (page 98, May 1978--Popular Science, Times Mirror Magazine Inc. 380 Madison Ave., New York, N.Y. 10017). This system is the closest state of art searched U.S. Pat. No. 3,981,258 Smith.
A thorough discussion of high speed sailboats is published in a book called the 40 Knot Sailboat U.S. Pat. No. 3,295,487 B. Smith. The best design put forward in this publication is a hydrofoil-borne sailing system which uses water exerted forces to balance wind tipping force. This system is no better than the one called the monomaran.
The physical forces applied to any sailing vehicle or wind driven vehicle are all similar yet the fastest sailboat has a velocity of 33 K, 37.125 mph. This compared to a land sailer or wheeled sailboat with speed capability of 80 mph, or any ice boat which obtains speeds of 100 mph or better, indicates that friction between the craft and its supporting surface radically affects the craft's speed capability.
Conventional sailboats most often carry parasitic weight or ballast well down in the boat to prevent the boat from being completely blown over by the wind. This is at best a compromise and wasteful. It restricts the payload of the craft and the speed at which it might travel.